You need a strip 8" x 45 1/2" long for your top border. This is how you'll start the quilt. I was able to get a full 8" x 44" piece of fabric after trimming my selvages. I also cut a 1 1/4" x 8" strip to add to the end of my 44" piece to give me the complete 45 1/2" in length. (See above) Press seams OPEN.
See that pretty row? Super cute! And the places for row 2's clamshells are already there!
Move the border piece to your sewing machine and topstitch as close to the edge of your clamshell as possible. I tried to zoom this picture as close as I could to show you. If you prefer a different applique stitch by all means use it. I want your finished project to be as much "you" as mine is "me".
Now, on to row 2.
Now a word if I may about the top-stitching. When you get to the bottom of those curves where they're so gently resting on the 'points' of the piece below- GO SLOW!!! If you have a needle down option on your machine- USE IT. I don't so I manually turned my needle down, pivoted my work and made ONE STITCH from one clamshell to the next. This kept them nice and close. Again, leaving my needle down, pivoted the piece and began stitching the next curve. I tried to get a picture of this but it really wasn't showing well. I think my description is enough.
Did I mention to GO SLOW!?
I could add 4 rows of clamshells before I ran out of pieces. Then, like I mentioned before I would press the next set and continue. The quilt top gets large, but not too large to handle if you take your time.
Here is a picture of the back after a few rows so you can see how nicely the pieces fit onto eachother.
After you have run out of clamshell pieces it's time to finish that quilt top. My quilt top had 16 rows (with a few extra clamshells leftover).
I pressed my entire quilt top just to be sure. Then it was time to trim. Using a LARGE ruler I trimed each side. Only a tiny bit was needed to clean up the edges.
See that beauty? Now we'll add the side borders. I cut (3) 5" x WOF strips for the side borders. I cut one in half and pieced each half to the other full strips, attached it to the quilt top sides and trimmed the excess. I know there's other ways of doing this so do whatever suits you. The yard of fabric I required is plenty for the borders.